Part 23 certification basis
Part 23 certification-basis support for equipment on normal-category aircraft
Part 23 certification-basis support helps a supplier whose equipment installs on a normal-category airplane establish and trace the basis its installation approval rests on. It is used by avionics and equipment teams whose article goes into airplanes certified under 14 CFR Part 23. The work fixes the applicable amendment, selects the consensus standards used as the means of compliance under the performance-based rule, and traces the installation evidence to each applicable section. You receive a basis map and a gap assessment ready for review.
When this review is needed
- Equipment is being installed on a normal-category airplane and the applicable Part 23 amendment has to be fixed before compliance work starts.
- The performance-based rule requires consensus standards to be selected as the means of compliance and the selection has to be justified.
- An installation touches sections whose applicability to the specific equipment is unclear and has to be reasoned through.
- A supplier wants the Part 23 basis and means of compliance read independently before the installation data goes out.
The problem
Part 23 moved to a performance-based structure where the rule states the safety outcome and accepted consensus standards supply the means of compliance, which puts the weight on selecting and justifying the right standard for each section. Suppliers carry over a basis from an earlier amendment without confirming it applies, pick a consensus standard without recording why it fits the equipment, and leave the applicability of marginal sections unresolved. An installation whose basis is loose draws applicability questions that should have been settled up front.
What gets reviewed
- The applicable Part 23 amendment for the airplane and the installation
- The performance-based sections that apply to the specific equipment
- Consensus standards selected as the means of compliance and the rationale for each
- How the installation shows compliance with each applicable section
- Equipment qualification and software data feeding the installation argument
- Applicability reasoning for sections at the margin of the equipment's function
What gets validated
- The applicable Part 23 amendment is fixed and matches the airplane and installation
- Every applicable performance-based section is identified for the equipment
- Each selected consensus standard is justified as a fit for the section it covers
- Installation evidence maps to each applicable section and supports the claim
- Equipment qualification and software data are consistent with the installation argument
- Marginal-applicability sections are reasoned through rather than left open
- The means-of-compliance plan reflects the standards actually used
Evidence normally required
- The airplane type data and the Part 23 amendment in question
- The equipment specification and its intended installation
- Any certification basis carried over from a prior program
- Qualification and software evidence assembled for the equipment
- The consensus standards proposed as means of compliance
Common discrepancies
- A certification basis carried over from an amendment that no longer applies
- A consensus standard selected with no recorded rationale for the fit
- Applicable performance-based sections missed for the specific equipment
- Installation evidence that does not map cleanly to an applicable section
- Marginal-applicability sections left unresolved into late review
- Qualification data inconsistent with the installation compliance argument
What is at stake
When the certification basis or the chosen means of compliance cannot be defended, the installation approval waits while the applicability of each section is argued. The delay holds the equipment off the airplane and consumes the engineering time the installation schedule assumed.
Move from findings to resolution
Identify gaps against the means of compliance.
How the work runs
Fix the amendment
Confirm the applicable Part 23 amendment for the airplane and the equipment installation.
Scope the sections
Identify the performance-based sections that apply to the specific equipment, including the marginal ones.
Select and justify
Choose the consensus standard as the means of compliance for each section and record why it fits.
Trace the evidence
Map installation evidence to each applicable section and produce a prioritized closure list.
What the buyer receives
- A Part 23 certification-basis map fixed to the applicable amendment
- A means-of-compliance plan with the consensus standard chosen for each section
- A section-to-evidence trace for the installation
- A prioritized list of the basis and compliance gaps to close
Who uses the output
- Certification leads preparing the installation approval data
- Engineering teams closing the section-level evidence gaps
- Program management sequencing the remaining compliance work
How the work fits into the transaction or program
The work supports the supplier's own Part 23 installation program. It fixes the basis and the means of compliance before the installation data is submitted so applicability is settled in the plan rather than argued in review.
Start with a single asset
Confirm requirements trace through verification.
Aircraft-specific considerations
Normal-category airplanes under this rule range widely in size, performance, and operating use. The sections applicable to a given equipment item depend on the airplane and the installation rather than on the part number alone, so the basis work is anchored to the specific airplane type data, not to the equipment in isolation.
Regulatory limits
Endeavor Elements supports the applicant's certification basis and compliance evidence. It does not establish the basis on the authority's behalf, accept a consensus standard, or guarantee approval. The authority sets the basis and makes the compliance findings.
What this review does not cover
- Establishing the certification basis on the authority's behalf
- Issuing any approval or making official compliance findings
- Performing the qualification testing itself
Specific to this review
- Under the performance-based structure, the rule states the safety outcome and accepted consensus standards supply the detailed means of compliance, so selecting and justifying the standard is the core of basis work.
- Carrying a basis over from an earlier Part 23 amendment without confirming applicability is a recurring finding, because the amendment fixes which requirements apply.
- A consensus standard chosen without a recorded rationale for its fit is treated as unsubstantiated even when the standard itself is accepted.
- Normal-category coverage under Part 23 spans a broad range of airplane sizes and uses, so the applicable sections for a given equipment item vary with the installation rather than being uniform.
Sources
U.S. Government (eCFR). Type certificates, STCs (Subpart E), TSO authorizations (Subpart O), PMA (Subpart K), and export airworthiness approvals (Subpart L).
Federal Aviation Administration. FAA type certification process, certification basis establishment, and compliance findings.
SAE International. Development assurance process at aircraft and system level, including requirements capture and validation.
Frequently asked questions
Why does the consensus standard selection matter so much under Part 23?
The rule is performance-based, so it states the outcome and the accepted consensus standard supplies the means of compliance. Choosing the right standard and recording why it fits is the substance of the basis work.
Can you work from a basis we used on an earlier Part 23 program?
Yes, but the first step is confirming the amendment still applies to this airplane and installation. A carried-over basis that no longer fits is a common finding.
Relevant glossary terms
Related pages
Where this fits
Talk to an engineer who has done this work
We will walk through your current state, the records or evidence involved, and a scoped first engagement.
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